Urgency urinary incontinence (UUI) and overactive bladder (OAB) can both potentially be influenced by commensal and urinary tract infection-associated bacteria. The sensing of bladder filling involves interplay between various components of the nervous system, eventually resulting in contraction of the detrusor muscle during micturition. This study models host responses to various urogenital bacteria, first by using urothelial bladder cell lines and then with myofibroblast contraction assays. To measure responses, we examined Ca2+ influx, gene expression, and alpha smooth muscle actin deposition assays. Organisms such as Escherichia coli and Gardnerella vaginalis were found to strongly induce Ca2+ influx and contraction, whereas Lactobacillus crispatus and L. gasseri did not induce this response. Additionally, supernatants from lactobacilli impeded Ca2+ influx and contraction induced by uropathogens. Upon further investigation of factors associated with purinergic signaling pathways, the Ca2+ influx and contraction of cells correlated with the amount of extracellular ATP produced by E. coli. Certain lactobacilli appear to mitigate this response by utilizing extracellular ATP or producing inhibitory compounds that may act as a receptor agonist or Ca2+ channel blocker. These findings suggest that members of the urinary microbiota may be influencing UUI or OAB. IMPORTANCE The ability of uropathogenic bacteria to release excitatory compounds, such as ATP, may act as a virulence factor to stimulate signaling pathways that could have profound effects on the urothelium, perhaps extending to the vagina. This may be countered by the ability of certain commensal urinary microbiota constituents, such as lactobacilli. Further understanding of these interactions is important for the treatment and prevention of UUI and OAB. The clinical implications may require a more targeted approach to enhance the commensal bacteria and reduce ATP release by pathogens.

22Urgency urinary incontinence (UUI), the result of conditions such as overactive 23 bladder (OAB), could potentially be influenced by both commensal and urinary 24 tract infection-associated bacteria. The sensing of bladder filling involves interplay 25 between various parts of the nervous system eventually resulting in contraction of 26 the detrusor muscle during micturition. Here we model host responses to various 27 urogenital bacteria, firstly by using urothelial bladder cell lines and then with 28 myofibroblast contraction assays. To measure responses, we examined calcium 29 influx, gene expression and alpha smooth muscle actin deposition assays. We 30 found that organisms such as Escherichia coli and Gardnerella vaginalis strongly 31 induced calcium influx and contraction, whereas, Lactobacillus crispatus and L. 32 gasseri did not induce this response. Additionally, supernatants from lactobacilli 33 impeded influx-and contraction induced by the uropathogens. Upon further 34 investigation of factors associated with the purinergic signaling pathways, we 35 found that influx and contraction of cells correlated to the amount of extracellular 36 ATP produced by E. coli. Certain lactobacilli appear to mitigate this response by 37 utilizing extracellular ATP or producing inhibitory compounds which can act as a 38 receptor agonist or calcium channel blocker. These findings suggest that members 39 of the urinary microbiota may be influencing UUI. 40 41 42 3 IMPORTANCE 43 The ability of the uropathogenic bacteria to release significant amounts of ATP as 44 an excitatory compound and possible virulence factor to stimulate various 45 signaling pathways can have profound effects on the urothelium, perhaps 46 extending to the vagina. This may be countered by the ability of certain commensal 47 urinary microbiota constituents, such as lactobacilli. The clinical implications are 48 to better understand the impact of antimicrobial therapy on the urinary microbiota 49 and to develop a more targeted approach to enhance the commensal bacteria and 50 reduce ATP release by pathogens.51 52 53 Patients who suffer from overactive bladder syndrome (OAB) or urgency 54 urinary incontinence (UUI) usually experience the sensation to urinate whether the 55 bladder is full or not. While there are many factors involved, ultimately it is the 56 contraction of bladder smooth muscle cells which invokes urination [1, 2]. Storage 57 and voiding of urine are controlled by sympathetic and parasympathetic pathways 58 [1,3], via the adrenergic and cholinergic systems. It has been speculated that 59 neurotransmitters with different effects and potentially originating from bacteria, 60 may play major roles in bladder function [4, 5]. 61The discovery of a urinary microbiota has shown that diversity differs 62 between healthy people and patients with neurogenic bladder dysfunction, 63 interstitial cystitis, UUI and sexually transmitted infections [6, 7, 8]. The microbial 64 diversity in women with UUI may be associated with severity of the condi...